Safety switch



A. L. FREHET.

SAFETY SWITCH.

APPLICATION nLED MAY 22. ma.

A. L. FRERET.

.SAFETY SWITCH.

APPucmon FILED' MAI22. 191s.

Patented Mar. I4, 1922.

3 SHEETS-SHEET 2.

/NVE/vof? M A TTOENEY A. L. FRERET.

SAFETY SWITCH.

APPLICATION FILED IAY 22, ISIS- 1,409,843. Patend Mar. 14, 1922.

3 SHEETS-SHEET 3.

P, I /N ENTUR 6 a. MKM

/Mw/Lf A T TOR/VE Y v particularly for use inconnection with cirlcuitsfof `corriparatively high ypotential such UNITED STATES PATENT OFFICE.

ARTHUR L. FBERET, 0F ENSLEY, ALABAMA.

SAFETY SWITCH.

Application led May 22,

To all whom it may concern:

Be it known that I, ARTHUR L. Fnnnnr, a citizen of the United States, residing in Ensley, Alabama, have invented certain new and 4useful Improvements in 'Safety Switches' of which the following-is a specification.

This 'invention relates to electric switches cominggenerally under the head of snap switches vor-cut-out boites and is designed as motor and main line feeder circuits.

One of the objects of the invention is the provision 'of a switch structure hav'inor a protecting cover which cannot be opened unless the switch blades have been previously operated: to breal'the circuit.

" Another object is to provide a structure in` which all the movable operating parts are carried by a hinged'cover which can be swung clear -of afxed back base`thereby giving free access to the termina-ls for adjustment or replacementI of fuses without the liability of having. the moving parts aceidentally operated.

Other objects are attained inthe embodiment herein 'described and shown in the ac' companying drawingsin which F lgfl is afront elevation of the improvedl 'switch with the front of the cover sectioned: f off las indicated by line 1- 1 of Fig. 42;

Fig. 2 is a'vertical sectional view taken on the plane indicated by the line 2 2 of Fig.

1; the'switch blades and the 4enclosing cover being tions; i

Fi 3 is a view similar to Fig. 2 butv showing t e enclosing cover and the switch blades in their respective open positions;

Fig. 4 is a sectional view on the plane indicated byline 4 4'of Fig. 1- the switch blades howeverfbeing shown'vin 4their open position in the tion;

Fig. 5 is a detail View of the switch operating mechanism the parts being shown in the positions they assume when the switch blades are in'closed position;

Fig. 6 is a similar view showing the positions assumed by the parts when the switch blades are in open position, being a section on line 6-6 of Fig. 4;

Fig. 7 is a detail showing the rectangular Switch shaft with the Switch blades secured thereto;

shown in their respective closed posi- Specilcation of Letters Patent.

interest of clearer illustra- Patented Mar. 14, 1922. 191s. serial Nausea-1.

Fig. 8 is a detail perspective view of the operating dog; and Fig. 9 is a detail perspective view of the locking bar.

AThe switch comprises a fixed back plate thereto which comprises atop 3. and short side walls 4 and 5 and a frontwall 6 extending downwardly therefrom. A hinged portion 7 formedin fthefront wall 6 forms a pivotai support for -the enclosing cover 8 which cover includes side walls 9 and 10, a front wall 11 and a bottom wall 12. A lug 13 is formed integral with the front wall 11 of the hinged cover and a similar lug 14 is formed on the front wall 6 of the fixed portion of the casing. V When the cover is in open position'the apertures 15 and 16 in the respective lugs 13 and 14 will come into register and as shown in Fig. 3 the'cover may be securely held in open position by inserting a pin 17 through the registering apertures.

All the movable parts of the switch mechanism are supported by the hinged enclosing Vcover and all electrical terminals and connections are carried or supported by the fixed back plate. It will thus'be seen that lwhen the cover is held in open position as the terminals and lswitch jaws for replacement or repair or the renewal of fuses.

The/hinged cover 8'is provided with a locking means actuated by the switch mechanism Iwhich co-operates'with a stationary jaw secured to the back plate. Y `This mechanismcomprises a locking bar .18 guided in brackets 19 and 2O secured to the side wall 9 of the cover. A spring 21 anchored to "pins 22 and`23 carried respectively by the bar 18 and bracket 2O serves to normally keep the locking barili the locked position shown in Fig. 2. At its upper end the bar 1V8 is provided with an angular lip 24 for engagement with one of the trip pawls of the switch mechanism to be hereinafter described.

The lower end of the locking bar 18'cooperates with a lug 25 formed on the fixed bracket 25 which is secured to the back base 1 to securely hold the cover in locked osition as long as the switch blades are c osed and in contact withtheir co-operating terminal switch jaws, When the switch 'mech- `1- having an overhanging hood 2 Vsecured f The feeder terminals 21S-2li enter the cas in.;r through suitable insulating bushings 274-27 in the top wall 3 of the casing 2 and vided with a slot 38 concentric ,with

are connected in the usual manner tothe switch terminals 2S- 28 hai-'ing downwarilly extending hiiurcated jaws 29-29 which project into recesses provided therefor 1n the insulating block 30 which is suitably secured to the back base 1.

The motor leads 31-31 are connected to the 'fuse terminals 32-32 secured to an instilating;r base 33 carried by the back hase l. Switch terminals 34-34 having jaws 35i-35 are secured to the upper part olL-the insulating base 33 and suitable replaceable fuses 36-36 are interposed between other'jaws 35'-35 of the switch4 terminals Ill-T34 and the jaws I32-32 of the motor outlet terminals 32;-32 in the usual well known manner.

Ain insulating barrier 37 is rigidly secured to the back base 1 of the switch and isprothe hinge 7 and terminating in un enlarged eircular inner orifice 39. This slot cooperates with the shaft of the switch mechanism to preventthe closing ofthe switch cover when the blades of the switch mechanism are in closed position, as will he hereinzt't'ter described. l Z i 'The switch mechanisniis carried whollyr by the hinged enclosing cover and is mounted therein in such a. way that it canhe easily Vand quickly removed for .replacement or re- :pair when necessary. y

This mechanism comprises a detachable: unitgzor `sub-assembly of parts. including' av .shaft i0 the greater part. of which Vis rectangular in cross-section as shownl-in Figs.. 4

and 7. The ends ofthe shaltaro cylindrical, one endA 41 is' supported in .a bearing.,r 42

whichis det-.reliably secured by. screws 43, to theside wall 1 0 of .the enclosingcover. The other cylindrical portion of .the` shaft 40,

. indicated :it 445 is of greater 'length and is:

jolvllflalled in :i suitable hearing formed in 50- the voperating dogg The duif :l5 is provided with a cvlilnlrical h nb .poijtioirlA 'whichl is rotatably mounted within. a snitalbleapertureiin Vthe side wallllof the hinged i 4B v removing the'. hearing 42, the

The dogl 45 (Fig. S) Vis also ,provided within square shank 47 for olriagcsiient with' `the operating handlef'lSsand an extended bifurcated jan' t9 for engagementwith a tenon 15.0 of 4the .control lever 50, lwhich is loosely niountcd onthe portion 4l of the operatingr -sha/t 40.

On either sideof the control lever (Figs.

,4,1rand'67) arelocated theoppositcly wound i wall 9ct the hinged cover.

' 62 lieyedvto the cylindrical portion elfi ofthe j blades (S3-453V and Across.-se'ction of, tthe shaft; 40,-f-is approxigot. the switch', .that if au opening-.movement .aj-)p rox i minitel the. minor axis of its erosslsection ,will be opposite the/arcuate slot-38 formed 'inlthe .bari-ier.:37.. -'l`he slot beingmf -greatemdepth volute springs .3l andil, the inner ends of which are lixeilly secured to the shaft 44 and the outer-'free'ends-"of which are hooked at walnjd 54 for engagement with the driving Vpin"55 carried by the control lever 50.

operates v-with trip pawls 57 and 58 which are pirot-allysecuiged at 59 and 60 to the side The control lewe' 3U is provided with a projecting pin 6l adapted to .alternately disengage the :trip pawls 5T and 58 from-the ratchet.56and .to also 'be engaged bythe hooked-tooth 5 :of the trip paw1 58. An i auxiliary vtrip cam operating shaft is adapted to engage the pin Gl of the control l-lever .to rotate the shaft 44 in the event that the spring snap. xnecha,nisni should 'for any reason fail to operate.:- Referring` tor-Figs. .4.-and 'i'stthe .switch (S4-*164, are .i secured.- in lore-tailed slots 65.-(55 of-thesjplit support :ferait-ing shafts 'InFig. 7 it .will -be seen that a. line passing throughtheinajorgaxisoi; the -1 mately at an anglegof, 45 degrees from-a. een- 'ter lineA passing throughth. lengthy@ he blades :63.

lVhen .the in. closedi.ipciisitiioiiy illustrated in Fig. 2 with .the blades -63. 63

`in the verticalcpositiomlthe im'ajorfaxis of the rectangular vsection of., the shaft? 4Q 'mill be at an angle-offapproximatelyidegrees ai th .the .horizontal f andz coincidetfy'vith a.-..

ra dial .1j ne .passinhnf throughthe hinge ,7; In this-position, as more clearly; seen.,in-.dotted reasoathe locking bar .18 didlgnot. operate toefeetively lock thecovertoithefbacltbase were f riren to the cover the same would be prevented from .openinghythe interference nl the sha-ft swithwalls ofi. the orifice-:39

formed inthe brindar-1.37. Hl'lowevelunwhen Vposition nis indicated in Eig-f3 thealilades and .the shafthav-ing-heen .rotated through 9D degrees -mllgiso..-p`osition the rectangular portion of the Shaftzthat:

than the minonaxis of theshaft will permit the shaftto ireelymass therethrough .when".

the cover ris. raised. .to -thef openreposition as clearly shown by. the dotted position y .which indicates an intermediate positioiriof 4the switch mechanism..

Ylil operationwhen the switch is closed the? parts are in the positions indicatediiin 130 "ratchet .3G keyed to the operating shaft cocannot be opened'without first moving the switch blades to their open position by operatin the handle 48 which act will raise ,f the loc in bar 18 by reason of engagement between t e lip 24 thereof with the trip l'pawl 57 which is raised to the position 'shown in Fig. 6 when the switch blades are opened..- Should the locking bar 18 tail to operate through breakage or any other reason the` rectangular portion of the shaft 40 Iwill be in such position (as indicated at m in dotted lines inFig. 3) as to prevent the passage of said shaft through the slot 38 'which-is of less width than the major axis ofthe rectangular portion of the shaft.

' When the switch blades are operated they "quickly sna. through an angle of approxi- 'mately- 90 egt l rested lby coming into contact with rubber 25 ees and their travel is arbumpers 70-70 carried by a lug 71 formed 'on the interior of the hinged cover.

7 The opening movement is effected b v turn- "ing the handle 48 which is carried by the squaredportioni? formed on the driving do f45 and its motion is transmitted by the bi urcatedend 49 to the control lever 50 the upper f end of said contro] lever.

by' engagement with a tongue 5()a formed on As thislever-is swung around in clockwise difrection as indicated by the arrow in Fig. 5,

' thepin 55 carried thereby will come into engagement with the hooked end 53 of the 'springl and a further movement thereof willvvind said spring around the shaft 44 lwhich at this time is held against rotation byfthe trip paw] 57 which is in engagement with the ratchet 56 secured to the shaft, the i action of which -is to store considerable torque lwithin thevolute spring 51.

'ti-nued movement of the handle 48 and oon- Control lever will bringt-he pin 6l carried by said control lever into engagement with -fthe 'underside of the trip pawl 57 and raise the same as shown in Wig. 6. This releases the ratchet 56 and permits the shaft 44 and the switch blades carried thereby to he quickly snapped around into a position shown in Fig. 6 by the energv previously stored in the volute spring` the movement of the switch blades being pnsitivelvstopped by coming into Contact with the rubber Shock absorbing bumpers carried by the ledge 71 of the cover. As the. trip paw] 57 was being raised by the pin Gl carried by the control lever 50. above described, its upward movement caused the locking har t8 to be also raised due to the engagement ot the lip 24 of the locking bar with the upper surface of the trip pawl 57. as indicated in Figs. 2, 3, 5 and 6, With the switch blades in this position the rectangular portion ot the shaft 40 will be so positioned that it will freely pass through the slot J-l in the insulating barrier 37 and the locking bar 18 will be raised a sufiicient distance to permit its lower end to clear the tooth 25 on the bracket 25, thus rendering all the parts in position to permit the switch cover to be swung upward about its hinge 7 to the position shown in Fig. 3, to permit Vaccess to the interior of the switch.

To effect the closing movement of the cover, the switch blades must be in the open position as illustrated in Fig. 3 so that the rectangular portion ot the shaft 40 will be able to enter the slot 38 of thev barrier andthe locking bar 18 set to clear the tooth 25 of the locking bracket 25. i

It is clear that should the switch-handle 48 be inadvertently moved so as t'o bring the switch blades into closed position when the cover is open it will be impossible to 'swing the cover about the hinge 7 to a position whereby the switch blades will come into contact with the jaws r29 and 35 due to the interference of the rectangular portion of shaft 40 and the barrier wall 37, as indicated by dotted lines at s in Fig. 3.

After the switch cover has been closed down it may be additionally locked by a- When the cover is locked 'in the position:

shown in Fig. 2, and the switch blades in the opened position indicated in dotted lines, the switch may be closed byv swinging the operating handle in the direction indicated by the arrow in Fig. 6. The closing operation heilig very similar to the above dcscribcd opening operation.

The driving dog 45 rot-ating the control llever 50 in the direction indicated permits the trip pawl 57 to fall into iosition to ronperatc with the ratchet. 56. nrt-herA movement. causes the pin 55 to engage the hooked end 54 of the closing spring 52. storing energy in the said spring while the trip pawl 58 engaging the ratchet 56 prevents the rolarg.' movementuntil the pin 6l of the| control lever is swung around to a posit-ion to trip the pawl 58 from engagement with its cooperating ratchet whereupon the switch blades will be quickly snapped to the position shown in Figs. 2 and 5. the movement of the control lever beingr arrested by the pin 61 engaging the hooked end 58n of the trip pawl 58.

Provision is made for opening the switch blades independent of the snap mechanism in the event that for any reason this mechanism should become inoperative due to the accidental breakage of one of the opening springs or failure of other parts to properly operate. This auxiliary operating means comprises the cam 62 keyed or otherwise secured to the switch shaft. The pin carried by the control lever 50 is of such length that it projects within the path of said cam 62 as shown at the left of Fig. 4. As thus constructed it is clear that if for any reason u n the rotation of the control lever in the dlrection indicated in Fig 5 the switch blades do not operate, a continued movement thereof will carry the pin 55 around and into engagement with the cam 62 which being keyed to the shaft will cause the rotation thereof thus effecting an opening movement of the switch blades.

Though I have`described with great particularity of detail the embodiment herein shown, it is not to be construed that I am limited thereto, as it is clear that structural changes may be made by those skilled in the art without departing from the spirit and scope of the invention-as set forth in the following claims.

What I claim is:

1. An electric switch comprising a Ahinged enclosing cover, a quick operating snap switch mechanism carried thereby including switch blades-carried bya shaft having a portion of non-circular cross section, a fixed back base, a lxed barrier of insulation secured thereto and having a slot therein which co-operates with said non-circular portion of said shaft to prevent the cover being either opened or closed when the switch blades on said Shaft are in closed position.

2. An electric switch comprising a hinged enclosing cover, a quick operating snap switch mechanism carried thereby including switch blades carried 'by a shaft having a portion of non-circular cross section, a fixed back base, a barrier secured thereto having a slot therein which eo-operates with said non-circular portion of said shaft to prevent the cover being either opened' or closed when the switch blades on said shaft are in closed position and means actuated by said snap switch mechanism whereby the said enclosing cover is locked to said fixed base when the switch is closed and unlocked therefrom when the switch is open. Y

3, In an electric switch a fixed back base, an enclosing cover hinged thereto, a slotted insulating barrier secured to said back base, a snap switch mechanism carried by said hinged cover having an operating shaft of non-circular cross section, means for quickly imparting a partial rotation of said switch shaft, the non-circular shaftand the slotted insulating .barrier being so associated that when the switch blades are in closed position the shaft will beso positioned that the walls of the barrier will prevent the cover from being swung on its hinge.

4. In an electric switch .a fixed back base, an enclosing cover hinged thereto, a quick snap spring actuatedswitch mechanism carried thereby having a shaft of non-circular cross section, a-barrier secured to2 saidfixed back base having .a'sltth'erein adapted to either prevent the opening or closing of said cover when the switch blades -are in closed position, and a1ocking- 1nechanism carried by said cover and associated withisaid switch mechanism and arranged ;to be locked and unlocked fthereby when the blades`A thereof are moved respectively in their closed and open positions. i w t 1 5. In an electriclswitch, a fixedback base, a cover hinged thereto,switch terminals carried by said back base, a sha-ft detachably `mounted in said cover which -is yprovided with at least two sets of-switch blades and means 4for effecting aquick opening and closing movement .of said blades,and a dielectric barrier secured to said back basefand,

ylocated between'said switch blades and terminals to prevent'arcingor. short circuiting between said terminalsl orswitch blades,-said barrierfha-v-iing a :slot formed therein to ypermit the rfree passage-.ofthe shaft therethrough when the switch blades are inopen position substantially as described.V

In Witness whereof, I have-hereunto signed my name.

A. L. FRERET. 

